Phonographic apparatus



Feb. 25, 1936. 'r. SACHTLEBEN 2,031,857

PHONOGRAPHIC APPARATUS Original Filed Jun 1, 1933 'IIIII/IIIII INVENTORlaw/refit: 7. 54- LEBE/V,

ATTORNEY Patented Feb. 25, 1936 UNITED STATES PATENT OFFICE PHONOGRAPHICAPPARATUS of Delaware Original application June 1, 1933, Serial No.

Divided and this application April 27,

1934, Serial No. 722,740

6 Claims.

This invention relates to phonographic apparatus and more particularlyto the variety thereof used for recording sound upon a photographicfilm, and is a division of my application Serial 5 No. 673,863 onphonographic apparatus filed June It'involves an improvement in soundrecording apparatus wherein the light reflecting mirror is actuateddirectly by the diaphragm as disclosed in Fritts Patent 1,203,190 andrelates more particularly to a number of improvements in the mirroractuating mechanism of such apparatus.

The particular apparatus herein described is especially adapted for usein a camera wherein the operator thereof records his descriptivediscussion while taking the picture.

Recording is accomplished by vibrating a narrow line of lighttransversely of a portion of the film, and this vibration of the line oflight is effected by the rotation or oscillation of a vibratable mirrorabout the axis of its support.

One object of the invention is to efiect the axial rotation of themirror by means of manually controlled adjustment for the purpose ofobtaining a zero setting thereof.

Another object of the invention is to provide means for retaining themirror spindle in predetermined relation to the driving rod of the dia-Phragm.

Another object of the invention is to provide means for pre-focusing theoptical system of the apparatus so that the recording units areinterchangeable without further adjustment.

means for damping cantilever vibrations of the mirror carrying spindle.

Another object of the invention is to provide means for retaining thedriving spindle and mirror spindle in co-operative relation, which willhave substantially no efiect upon the frequency characteristics of theapparatus.

In the drawing:

Fig. 1 is a rear view of a mirror driving mechanism made in accordancewith my invention.

Fig. 2 is a sectional view along the middle of Fig. 1.

Fig. 3 is an enlarged view corresponding to the middle portion of Fig.1.

Fig. 4 is an enlarged view showing a modification of the driving rod andmirror spindle connections.

Fig. 5 shows the casing of the recording unit and the means for secm'ingaccurate adjustment thereof in relation to the film position.

Another object of the invention is to provide Referring first to Figs. 1and 2: A sound-box is provided enclosing the diaphragm I, whichsound-box has a cover 2 fitted with a mouthpiece 3, as well as a rearcover 4. Through the rear cover 4 extends the driving rod 5 which isconnected to the diaphragm I and vibrated longitudinally thereby.Pivoted against the driving rod 5 is the mirror spindle 6, which isillustrated as a rod diamond-shaped in cross-section but may be of anyother suitable form. Carried upon one extremity of the rod 5 is themirror 1 from which light is reflected to the recording surface.

The other of the acute angles of the diamondshaped rod is pivotedagainst the supporting member 8 which forms a fixed pivot therefor.

It will be apparent that sound waves impinging upon the diaphragm willproduce longitudinal movement of the rod 5 which will rotate oroscillate the mirror spindle 6 about its pivot in the supporting member8, and thereby cause shifting of the beam of light which is reflectedfrom the mirror. The optical system for focussing the beam of light uponthe mirror and converging it into the form of a narrow line upon thefilm, is no part of this invention and, so far as this invention isconcerned, it is immaterial what form it may take although the generalarrangement shown in Taylor Patent 1,847,636 is quite satisfactory. Itsconstruction and arrangement will be readily understood by those skilledin the art.

The member 8 is supported upon the member 9 which in turn is adjustablysupported upon the rear face 4 of the sound-box.

The member 9 is, as shown, of a T-shape with the ends of the cross-barthereof fastened to the cover 4 by the screws Ill. The middle of thisportion is supported upon the case by the pin H which is set into themember 4 and upon which the member 9 can be moved. The screws Ill bendthe member 9 very slightly over the member ll upon which the member 9 isto be rotated by pressure applied at the extremity of the other legthereof. This rotation is afifected by actuation of the screw l2 whichis threaded into the member 4 and also into the member 9. As will beseen from Fig. 2, the portion of this screw which is threaded into themember 4 is of relatively large diameter while the portion threaded intothe member 9 is of similar diameter, and the pitches of the threadsthereon are in correspondence with these diameters. Due to thediiferential action therebetween, a very fine adjustment of the positionof the member 9 can be secured,

- when the member is held rigidly m such adjustthe mirror I.

The member 8, which is provided with notches for pivoting the spindle 6,is secured to the member 9 by the screws l3 which holds it firmlyagainst the pins l4 over which it is slightly flexed to prevent anyindependent vibration thereof. Since the pins H are located in themiddle of the member 8 and the screws l3 are located at the endsthereof, the member 8 can be rotated on the pins M as a pivot for thepurpose of securing proper alignment of the spindle 6, by loosening oneof the screws I3 and tightening the other.

There may be some tendency for the spindle 6 to vibrate laterally. Anysuch vibration may be prevented in the manner shownin Fig. 3 wherein asmall arm i5 is attached to the T-bar 9 and extends outwardly therefrompast the spindle 6. A small pad of rubber I6 is secured to the arm I5and rests lightly against the spindle 6. This block of rubber serves todamp out any cantilever vibrations of the spindle 6 while at the sametime it does not interfere with the freedom thereof to rotate.

Fig. 4 shows a slight modification of the construction shown in Fig. 2.In this figure the driving rod 5 is maintained firmly against thespindle 6, and this spindle is in turn maintained securely against themember 8, by the action of a spring II. This spring I! is secured to apin I8 in the member 9 and the end of the spring extends over a spacingblock IS on the member 8. This end of the spring is attached to themember 5 in the grooveZll as shown.

It will be apparent that the spring l1 maintains the elements 5, 6 and 8in proper relation to each other and, since the tension of the spring istransverse of the rod 5 and the material of the spring is quiteflexible, it does not interfere with longitudinal vibrations of themember 5.

It will be apparent that other types of vibration-converting means otherthan the mirror I 30. This drum isrotated upon a shaft 3| and concentricwith the shaft 3|.

coaxial with it is located a bushing 32 of predetermined diameter. It isimmaterial whether this bushing is fixed to the shaft or to the frame,or whether it rotates or stands still. The bushing is obviously circularand has its circumference In any case, the periphery of the bushingdefines a predetermined distance from the shaft which in turn definesthe positioning of the optical system in the manner hereinafterdescribed. The mirror vibrating mechanism described above is mounted atthe right-hand end of the casing 33 as indicated and this casing 33contains the exciter lamp and the remainder of the optical system whichis of such a nature as to be able to focus the required fine line oflight upon a strip of film passing over the be focussed upon the saidfilm.

drum 38, this line of light passing out of the easing 33 through anaperture in the plate '34.

The casing 33 is secured to a portion of the camera or recorder frame 35by means of the screw 36 or as many similar screws as may be necessaryor desirable, and these screws pass through elongated holes-in thecasing 33 so that a slight movement of the member 33 toward or away fromthe sprocket 38 is permitted. v In the casing 33 is drilled a hole ofappropriate diameter into which is fitted a pin 31 which is secured inplace by a screw 38. In manufacturing the device, the casing 33, whenthe optical system has been completely assembled, is placed in a jig andshifted until the optical system is in correct focus. The pin 31 is thenextended until it contacts with a stop member in the jig and issecuredfirmly in place by tightening the screw 38. By this means the endsurface of the pin 31 is maintained in uniform relation to the focalplane of the optical system.

If the bushing 32 is made of appropriate diameter, then when the unit 33is inserted into the camera and brought to such a position that the pin31 contacts with the bushing 32, the optical system will be accuratelyfocussed upon a film upon the sprocket 38.

It will be apparent that these recording units are not merelyinterchangeable with each other but can be exchanged between differentrecorders or cameras without refocussing.

The scope of this phase of the invention is not limited to directlyactuated recording apparatus as, it will be apparent that a recordinggalvanometer or any equivalent apparatus which is provided with suitablemembers for abutment against and cooperation with the fixed members ofthe recording device may be substituted, and the camera or recorder canaccordingly be used interchangeably for various purposes, according towhich type of device is included therein.

I claim:

1. Phonographic apparatus comprising a drum adapted to support a filmand to convey it past the translation point, a unitary optical systemadapted to focus a beam of light upon the said film at the saidtranslation point, a bushing in concentric relation with the said drum,and a member in predetermined co-operative relation with the saidoptical system adapted to abut against the bushing whereby when saidmember and said bushing are in abutment, the optical system will befocussed upon the said film.

2. Phonographic apparatus comprising a drum adapted to support a filmand to convey it past the reproduction point, a unitary optical systemadapted to focus a beam of light upon the said film at the said point, abushing in concentric relation with the said drum, and an. adjustablemember adapted to abut against the first bushing and in predeterminedco-operative relation with the said optical system whereby whn saidmembers are in abutment, the optical system will be focussed upon thesaid film.

3. Phonographic apparatus comprising a drum adapted to support a filmand to convey it past the reproduction point, a unitary optical systemadapted to focus a beam of light upon the said film at the said point, afixed member in predetermined relation to the said drum, and a secondmember in predetermined co-operative relation with the said opticalsystem adapted to abut against the first member whereby when saidmembers are in abutment the optical system will 4. Phonographicapparatus comprising a drum adapted to support a film and to convey itpast the reproduction point, a unitary optical system adapted to focus abeam of light upon the said film at the said point, a fixed member npredetermined relation to the said drum, and an adjustable second memberadapted to abut against the fixed member and in predeterminedco-operative relation with the said optical system whereby when saidmembers are in abutment the optical system will be focussed upon thesaid film.

5. A unitary structure including means for acoustically modulating abeam of light, means for directing said beam to a focal point exteriorto said structure, and a member extending from said structure in apredetermined relation with said point.

6. In phonographic apparatus, means for moving film past a recordingpoint and a stop in predetermined relation to said recording point incombination with a unitary structure including means for acousticallymodulating a beam of light, means for directing said beam to a focalpoint exterior to said structure, and a. member extending from saidstructure in a predetermined relation with said point, the said memberabutting the said stop whereby the said beam is fo cussed upon the saidfilm.

LAWRENCE T. SACHTLEBEN.

